The present invention refers to an improvement in the forced air flow system for refrigerators having at least two refrigeration environments, particularly used in refrigerators and freezers in which the evaporator is provided externally to the refrigeration environments and which have independent refrigeration air circuits communicating each refrigeration environments with the evaporator.
In the refrigerators having two or more refrigeration environments, for example a freezing compartment and a refrigerating compartment, and in which the evaporator is provided externally to said refrigeration environments, the refrigeration of the latter is obtained by forced circulation of air flows through the evaporator, said forced circulation being made by an impelling means, usually a fan provided adjacent to an air passage between the freezing and refrigerating compartments.
In some known constructions, the air flow of the different refrigeration environments of the refrigerator is mixed in a return duct of a refrigeration air circuit, which duct is common to said compartments, said air flow being then conducted to the environment of the evaporator and cooled therein, before re-conducted to these compartments. Since the conditions of temperature and air humidity in these environments are distinct, the mixture of air flows to promote the refrigeration of these environments, by passing through the evaporator, results in energetic losses.
In other known constructions, the refrigerator has, for each refrigeration environment, a respective refrigeration air circuit which communicates the air flow of the respective environment with the environment of the evaporator. In these constructions, the air flow of each refrigeration environment is forced to pass through the evaporator, through the respective air circuit, which is provided with a respective fan.
In these constructions, in order that the air flows do not mix, even in the region of the evaporator, it should be provided, for each refrigeration circuit, respective components, including for example, the evaporator, which increases the cost of the product. Besides increasing the cost of the product, a higher number of components makes more complex the assembly of this product and leaves this product more susceptible to failures, requiring more frequent maintenance service.
As a function of the limitations of the available space for installing the components, such constructions require smaller mechanical components, which usually have low efficiency, causing losses. Moreover, a higher number of components allows the occurrence of noises.
Thus, it is an objective of the present invention to provide an improvement in the forced air flow system for refrigerators, which allows a substantial segregation of the forced air flows between the refrigeration environments, with a simple construction, of easy assembly and maintenance, which uses few components, but with a low cost. These and other objectives are achieved by an improvement in the forced air flow system for refrigerators, comprising: at least two refrigeration environments; and refrigeration air impelling means, having a suction side and a discharge side and forcing the passage of an air flow from a refrigeration environment through a respective evaporator portion, each evaporator portion having an outlet side opened to a respective refrigeration environment, the refrigeration air impelling means comprising only one fan associated with at least two suction chambers, which are each opened to a respective refrigeration environment and to at least two discharge chambers, which are each opened to an inlet side of a respective evaporator portion.